Valve spool detents for manually positioned spool valves have been in existence since the early days of hydraulic valves. The prior art includes a wide variety of spring means for urging a ball against a lug or into a groove, as exemplified in the Meisel U.S. Pat. No. 3,602,245. Most of these prior art methods utilize some form of a compression coil spring which urges the ball directly into the detent or through a cam as exemplied in the FIGS. 4 through 7 of the last-mentioned patent. The usage of a c-shaped spring rather than a coil spring was done in the prior art in Stephens, et al, U.S. Pat. No. 3,218,882 and Daggy, U.S. Pat. No. 3,608,586. The last-mentioned patent to Daggy utilizes a c-spring on a pair of friction pads to apply a constant drag on the valve spool rather than a detent structure. The Stephens, et al patent does utilize a flat c-shaped spring for urging balls constantly outward against a detent groove.